Roger K Lake | Searcharxiv

arXiv2021

Magnetic Properties of NbSi2N4, VSi2N4, and VSi2P4 Monolayers

The recent demonstration of MoSi2N4 and its exceptional stability to air, water, acid, and heat has generated intense interest in this family of two-dimensional (2D) materials. Among these materials, NbSi2N4, VSi2N4, and VSi2P4 are semiconducting, easy-plane ferromagnets with negligible in-plane magnetic anisotropy. They thus satisfy a necessary condition for exhibiting a dissipationless spin superfluid mode. The Curie temperatures of monolayer VSi2P4 and VSi2N4 are determined to be above room temperature based on Monte Carlo and density functional theory calculations. The magnetic moments of VSi2N4 can be switched from in-plane to out-of-plane by applying tensile biaxial strain or electron doping.

cond-mat.mtrl-sci↗

arXiv2016

Uniform Benchmarking of Low Voltage Van Der Waals FETs

Monolayer MoS2, MoSe2, MoTe2, WS2, WSe2, and black phosphorous field effect transistors (FETs) operating in the low-voltage (LV) regime (0.3V) with geometries from the 2019 and 2028 nodes of the 2013 International Technology Roadmap for Semiconductors (ITRS) are benchmarked along with an ultra-thin-body Si FET. Current can increase or decrease with scaling, and the trend is strongly correlated with the effective mass. For LV operation at the 2028 node, an effective mass of ~0.4 m0, corresponding to that of WSe2, gives the maximum drive current. The short 6 nm gate length combined with LV operation is forgiving in its requirements for material quality and contact resistances. In this LV regime, device and circuit performance are competitive using currently measured values for mobilities and contact resistances for the monolayer two-dimensional materials.

cond-mat.mes-hall↗